Chap. IV. 2.] metamorphic rocks, 105 



spring sites at Cajareputty and Tripunguly not having been exposed to 

 any marine denudation which would most likely have obliterated all 

 traces of them. The period of the activity and cessation of those min- 

 eral springs would, therefore, date subsequently to the great elevatory 

 movement which finally raised the cretaceous rocks lying to the east of 

 the magnesites above the level of the sea of that remote time. 



The " Chalk Hills " equally would appear to have been subjected to 

 the"" erosion of atmospheric agencies only, but the thermal waters which 

 gave rise to the phenomena seen there may have been active during the 

 Cretaceous period, as, from their greater elevation of nearly 1,000 

 feet above the existing sea level, these hills may have still been above the 

 level of the rather shallow sea indicated by the peculiar fauna of those 

 ancient sedimentary rocks, more especially in the Trichinopoly and 

 Arrialoor groups. 



{ 327 ) 



